Generally, a wireless telephone includes a main body and an antenna. The main body is designed compact so that an user can carry it within his hand. The antenna is provided to receive and send radio signals. A key operation part which includes a ten-key is provided in the main body so that the user can input a telephone number and perform a remote control through a push-tone service or push-button telephone service.
Since calling information from the wireless telephone to the other telephone or station are transmitted in the form of digital signals, dial pulses or push tones are not necessary to the wireless telephone, but tile wireless telephone should be provided with a push-tone signal mode so as to be enable to take advantage of the push-button telephone service.
When the user of tile wireless telephone uses the push-button telephone service, the user should switch the mode of the wireless telephone into the push-tone signal mode. With the push-tone signal mode, the push-tone signals are generated and output from the wireless telephone. Further, since generally the wireless telephone is provided with more than one push-tone signal mode, it is necessary to display which signal mode is now set up. Usually, a display for indicating the signal mode is provided in the main body of the wireless telephone, and the user should confirm which signal mode is now set up by seeing the display every time he uses the wireless telephone.
With the conventional wireless telephone, the user cannot know the signal mode until he sees the display. As a result, the push-tone is unexpectedly generated if the user accidentally touches the ten-key during the telephone communication, or the push-tone is not generated when the user wants to generate it.
In addition, when the user refers to a bank account or performs a remote control savings transfer or train reservation, the conventional wireless telephone outputs the push tone for only 100 msec or so regardless of a key-pressing period of time. Consequently, under a bad radio wave condition, sufficient instruction signals are not transmitted from the wireless telephone and this results in a false signal transmission.